Inductive Mobile Device Charger

ABSTRACT

Wireless Mobile Device Charging Mat Charm with clip and battery and with or without retractable cord to re-charge the charging mat is disclosed. This invention eliminates the problem of leaving phone charging mats behind when traveling or on the go. This invention eliminates the problem of not being able to charge a phone when electricity is not available.

RELATED APPLICATIONS

This application is a divisional of the U.S. Utility patent applicationfor “Inductive Mobile Device Charger,” Ser. No. 15/249,209, filed onAug. 26, 2016 and currently co-pending, which in turn claims the benefitof priority to the U.S. Provisional Patent Application for “WirelessMobile Device Charging Mat Charm with clip and battery and with orwithout retractable cord to re-charge the charging mat,” Ser. No.62/211,130 filed on Aug. 28, 2015.

FIELD OF THE INVENTION

The present invention pertains generally to chargers for mobileelectronic devices. More particularly, the present invention pertains toa mobile device charger using inductive coupling with a mechanism forconvenient storage of the cable and increased portability of thecharger, and attachment of the charger to a purse or backpack. Thepresent invention is particularly, but not exclusively, useful as apersonal electronic device charger for persons temporarily in placesaway from home.

BACKGROUND OF THE INVENTION

Electricity is not always available to use to charge phones and mobiledevices. Mobile device charger cords and metal tips are exposed todamage because they are not protected. In addition, people leave mobiledevice chargers at home and in hotel rooms, resulting in loss of thecharger and depletion of the battery within the device.

Existing Wireless Charging Mats are not Bag Charms and cannot beattached to other objects such as purses, pant loops, computer bags,necklaces. Therefore, they are easy to leave behind and hard to carry.Existing electric mobile device chargers do not have batteries builtinto them. They are disorganized, easily forgotten and easily broken.

The present invention allows the user to charge their mobile deviceeither from the battery or using an external power source while it isstill attached to their bag so that they do not forget it in the outlet.

This invention eliminates the problem of leaving phone charging matsbehind when traveling or on the go. This invention eliminates theproblem of not being able to charge a phone when electricity is notavailable.

Mobile device chargers provide a means for charging the batteries ofpersonal electronic devices by connecting them to a power source. Thepower source to which a mobile device charger connects is generallyeither a standard power outlet in a building or a vehicle's power sourcethrough a cigarette lighter outlet or dedicated charging port.

Mobile device chargers currently offered for sale are easily damaged.The cords and connectors are not protected by the charger itself, and sothey often sustain damage through exposure to people, pets, or otherobjects. Additionally, currently available mobile device chargers areoften accidentally left at home or away from home in places where theowner was using them, such as offices or hotel rooms. Thus, special caremust be taken to avoid damage or loss of currently available mobiledevice chargers.

In light of the above, it would be advantageous to provide a device forinductive charging of portable electronic devices that is durable, easyto use, and comparatively cost effective.

SUMMARY OF THE INVENTION

One object of the present invention is convenient portability andstorage of a mobile device charger. Another object of the presentinvention is the avoidance of damage to a mobile device charger or lossof the charger.

As stated above, electricity is not always available to use to chargephones and mobile devices. In addition, users of phones often leavetheir phone charger behind when traveling or on the go. The inventionclaimed here solves this problem. The present invention allows the userto carry a wireless mobile device charging mat attached to a purse,backpack or computer back so that it is not left behind when travellingor on the go.

The claimed invention differs from what currently exists. We are notaware of any wireless mobile device charging mat enclosed in a bag charmthat exists today. Existing wireless charging mats are not bag charmsand cannot be attached to other objects such as purses, pant loops,computer bags, necklaces.

This invention eliminates the problem of leaving phone charging matsbehind when traveling or on the go. This invention eliminates theproblem of not being able to charge a phone when electricity is notavailable.

Existing mobile device chargers do not have a clip on them to allow themto be attached to anything else, so they are easily forgotten. Existingmobile device charger cords and metal tips are often damaged becausethey are exposed.

The present invention includes a wireless charging mat to charge mobiledevices and display advertisements, logos, etc., a housing under the matto hold a battery and a built in electrical plug, a charm clip to attachthe mat to other objects such as purses or belt loops, a battery tocharge a mobile device when an electrical outlet is not available, andan electrical plug built into the housing.

The present invention consists of a protective enclosure containing aninductive coupling charging circuit. A mobile device sitting on top ofthe present invention is charged through inductive coupling. Analternative embodiment includes a retractable cable with a connector atthe end. The connector plugs into a power source such as a USB port inorder to pass current from the power source to the inductive couplingcharging circuit to charge the internal battery. When the invention isnot in use, the enclosure protects the retracted cable and itsconnector, thus avoiding damage to the cable or connector. In analternative embodiment, the cable and connector also provide currentfrom the inductive mobile device charger to a mobile device, providingthe additional ability of charging a mobile device that doesn't supportinductive charging.

An alternative embodiment includes a USB port in conjunction with amobile device charging circuit. The USB port and corresponding chargingcircuit allows for charging a mobile device that lacks support forinductive charging.

The enclosure on the present invention includes a connector for a chain.In one embodiment, this is a recessed part of the enclosure in which oneside of the enclosure connects to the opposite side over the recess viaa bridge or rod extending across the recess. A chain may be attached tothe bridge or rod. In an alternative embodiment, the enclosure isextended on one end and the connector consists of an opening in theextension through which a chain may be connected. A clip or keychain maythus be attached to the enclosure through a cord or chain. By attachingthe invention to another object via the clip, loss of the mobile devicecharger can be avoided.

A preferred embodiment of the present invention uses a transformer tocharge an internal battery, with a flyback controller on the primaryside of the transformer and a synchronous rectifier circuit on thesecondary side. The flyback controller switches the rectified maincurrent through the primary side of the transformer at approximately 80kHz. The switching speed is dithered to lessen harmonic content and easeEMI compliance. The resulting current is monitored by the flybackcontroller on an auxiliary winding on the primary side of thetransformer, allowing the controller to protect against over-voltage andover-current conditions and the current to be monitored entirely on theprimary side of the transformer. The secondary side of the transformercontains a synchronous rectifier circuit in place of the traditionaldiode, greatly improving the efficiency during use by removing thevoltage/power loss across the diode. Further, when the load is removedentirely, a monitor circuit issues a special set of pulses through thetransformer indicating to the primary-side flyback controller that thereis no load, causing it to enter a low-power standby mode. This featureresults in virtually zero standby power when the adapter is notconnected to a device.

A preferred embodiment of the present invention includes a foldable plugthat sits flush with the enclosure when folded in, but may be extendedin order to connect to a power source. In one variation of saidembodiment, a recess around the folded plug allows easy access to theplug in order to extend it. In another variation, the ends of the plug'sprongs, when folded in, sit against the edge of the enclosure, allowingextension by grasping the end of said prongs and pulling outward via amotion of the hand against the edge of the enclosure. By folding in theplug so that it sits flush with the enclosure, the mobile device chargermay be easily transported in a pocket or a purse without damaging otherobjects stored with it.

Also, a preferred embodiment of the present invention uses a cylindricalenclosure with rounded or beveled edges which allow it to easily becarried in a pocket or a purse without damaging other objects storedwith it.

A battery is included inside the enclosure in an embodiment of thepresent invention, thus allowing the mobile device charger to providecurrent to a mobile device when no outside power source is available.Some embodiments may further include a receiving coil and relatedcharging circuit to charge the internal battery via inductive chargingfrom another mobile device charger, thus allowing the mobile devicechargers of the present invention to charge each other. In this way,various mobile device chargers of the present invention can be stackedon top of each other and their internal batteries charged throughinductive charging via a single original power source. The originalpower source may be a single household power outlet, which would sufficeto simultaneously charge multiple mobile device chargers of the presentinvention.

A stand in an embodiment of the present invention is formed by a leverattached to the bottom of the wireless charging mat which sits flush ina first configuration and pivots outward and locks into various anglesin other configurations. By locking the lever at an angle from the restof the charging mat, the charging mat may be seated on a desk or tableat an angle from the horizontal, allowing convenient use of the mobiledevice while the device is being charged.

A preferred embodiment of the present invention is made up of stackablemodules. One module is the charging mat itself and includes theinductive charging circuitry. Another module provides the battery and athird module provides the power cord. The user can stack all threemodules on top of each other, or use only the modules needed. Forexample, if the user is on the road and will not be able to use a poweroutlet, the power cord module may be left behind for the sake ofconvenience and portability. At home, the battery module may not bewanted. A stand may be formed with a lever attached to a base module orthe bottom of any module. The lever sits flush with the base or modulein a first configuration and pivot outward and lock into place atvarious angles in alternate configurations. Finally, battery chargingcircuitry allows the battery module to charge its internal battery whenthe invention is placed on another inductive mobile device charger.

A preferred embodiment of the present invention has a diameter ofroughly 4 inches, or about 10 centimeters, which would be appropriatefor charging most inductive-charging ready mobile phones. A rectangularembodiment would have a length of roughly 4 inches for the same reasons.Other embodiments have larger diameters or lengths for greaterconvenience in charging tablet computers. Embodiments of the presentinvention include other sizes as appropriate for charging various typesof electronic devices, such as watches, jewelry, and step counters.

The Components are related as follows: The wireless charging mat is usedto charge phones. The charm housing is attached to the mat and is usedto hold the battery and the folding electrical plug. The charm clip isattached to the wireless charging mat and the housing to other objects.The battery is used to charge mobile devices. The folding electricalplug is used to charge the battery and provide power to the wirelesscharging mat charm.

The Invention Works as follows: The wireless charging mat charm is usedto charge phones. The charm housing is attached to the mat charm and isused to hold the battery and the folding electrical plug. The charm clipis used to attach the wireless charging mat charm and the charm housingto other objects. The battery is used to charge mobile devices. Thefolding electrical plug is used to charge the battery and provide powerto the wireless charging mat charm.

In order to make the invention, a person would make a wireless mobilecharging mat and attach it to the housing. Then, insert a battery insidethe housing and add a folding electrical plug. Then, a person would adda chain, rope, elastic or another type of cord and a clip. The battery,the wireless charging mat charm, the housing and a power source are allnecessary. A USB port could be added to charge the battery. Aretractable charging cord could be added to coil into the housing. A carcharging plug could be added to charge the battery. If a USB port or acar charging plug was added, the folding electrical plug could beremoved.

To use the invention, a person would attach the wireless mobile devicecharging mat charm to their purse, bag or backpack, belt loop ornecklace, etc. and carry it with them so that they do not leave itbehind when traveling or on the go. The person would charge their mobiledevice using the invention when they do not have access to electricity.A person would re-charge the mat charm when it runs out of power.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself,both as to its structure and its operation, will be best understood fromthe accompanying drawings, taken in conjunction with the accompanyingdescription, in which similar reference characters refer to similarparts, and in which:

FIG. 1 is a top view of an inductive mobile device charger with a chainfor convenient attachment of the charger to another object;

FIG. 2 is a side view of an alternative embodiment of the presentinvention showing a retractable USB cable;

FIG. 3 is bottom view of an inductive mobile device charger;

FIG. 4 is a diagram showing the major components of the inductivecharging system of a preferred embodiment of the present invention;

FIG. 5 is a schematic diagram showing the layout of electricalcomponents in an AC/DC converter circuit used in charging the internalbattery in a preferred embodiment of the present invention;

FIG. 6 is a perspective view of an embodiment of the present inventionshowing various modules comprising the elements of a mobile devicecharger which are stacked on top of each other; and

FIG. 7 is a side view of an embodiment of the present invention showinga lever which allows the mobile device charger to sit at an angle forconvenient use of a mobile device during charging.

DETAILED DESCRIPTION

FIG. 1 illustrates a top view of a preferred embodiment of an inductivemobile device charger 100 comprising an inductive charging circuitinside a housing 102. Housing 102 has a front face 104 on which a logoor advertisement may be displayed. A chain 106 is attached at one end tothe housing 102 by a connector 108. A loop 110 is attached to the otherend of chain 106, allowing the inductive mobile device charger 100 to beattached to a purse or other object. Loop 110 may be replaced by a clip,keychain, or other attachment in various embodiments of the presentinvention. The inductive mobile device charger 100 charges a mobiledevice sitting on its front face 104 through inductive coupling.

FIG. 2 illustrates a side view of an alternative embodiment of ainductive mobile device charger 100 which includes a charging connector112 attached to the inductive mobile device charger 100 via aretractable cable 114. The charging connector 112 and retractable cable114 allow charging the internal battery of the inductive mobile devicecharger 100 via an alternative power source. In a preferred embodiment,the charging connector 112 is a USB connector, allowing the mobiledevice charger 100 to use power from a USB port to charge the internalbattery. A USB charging port 115 allows a user to connect and charge apersonal electronic device that does not support inductive charging fromeither the internal battery of the mobile device charger 100 or itsexternal power source.

FIG. 3 illustrates back view of an inductive mobile device charger 100,showing back face 116 on which sits an electrical plug 118. Theelectrical plug 118 provides power to the inductive mobile devicecharger 100 in order to charge a mobile device. Alternatively,electrical power is provided to the inductive mobile device charger 100through electrical plug 118 in order to charge an internal battery. Theinductive mobile device charger 100 then uses internal battery power tocharge a mobile device, allowing charging to take place when anelectrical socket is unavailable.

FIG. 4 illustrates the primary components and functionality of aninductive mobile device charging system 200 comprising an inductivemobile device charger 100 and a mobile device 204. A power source 206,such as an internal battery or rectified current from a power outlet,provides power to an inverter 208. The inverter 208 provides an ACwaveform to a primary coil 210. In a preferred embodiment, the frequencyof the waveform is between 100 and 200 kHz. In a preferred embodiment,the inverter 208 transfers power to the primary coil 210 by afull-bridge switching arrangement at a 50% duty cycle and a 130 kHzswitching frequency. It is to be understood, however, that differentfrequencies may be used according to the needs of any individualproject. A voltage sensor 212 monitors the primary coil 210 and providesdata to a controller circuit 214. The controller circuit 214 in turnadjusts the output of the inverter 208 in order to provide an amount ofpower appropriate to the load provided by the mobile device 204. Thevoltage sensor 212 and the controller circuit 214 may also detectcommunications from the mobile device 204 and respond by increasing,decreasing, or shutting off the provided power.

The alternating current through the primary coil 210 creates a magneticflux, which in turn creates an alternating current in a secondary coil216 inside the mobile device. The current is rectified by a rectifyingcircuit 218 and passed on to the load 220. A controller circuit 222 incommunication with both the rectifying circuit 218 and the load 220causes signals to be sent to the inductive mobile device charger 100requesting the amount of power needed by the load 220. In mostinstances, the load 220 will comprise a battery, and the power necessarywill vary depending on the amount of charge already present in thebattery. The controller circuit 222 of the mobile device 204 maycommunicate with the controller circuit 214 of the inductive mobiledevice charger 100 through backscatter modulation by brief alterationsof the load placed on the secondary coil 216, which in turn are detectedby the voltage sensor 212 in the inductive mobile device charger 100.Additionally, in some embodiments, communication across the primary coil210 and secondary coil 216 may be accomplished through frequency-shiftkeying.

In a preferred embodiment of the invention, power source 206 comprises abattery as well as its own secondary coil, rectifier, and controller,which act as load 220, secondary coil 216, rectifying circuit 218, andcontroller circuit 214, respectively. Such a configuration allowsmultiple mobile device chargers 100 to be stacked onto each other, thusallowing for the simultaneous charging of the internal batteries of eachmobile device charger 100. Such a configuration is particularly usefulwhen multiple mobile device chargers 100 need to be charged, but only asingle power outlet is available.

FIG. 5 is a schematic of an AC/DC converter circuit 300 as used incharging the internal battery in a preferred embodiment of theinvention. The AC input is passed through initial rectifier 302 to aprimary side flyback controller 304. A low-profile transformer 306 thensteps down the voltage. A wake-up monitor and synchronous rectifier 308on the secondary side of the transformer detects the presence or absenceof a load, and signals the flyback controller 304 accordingly. Thewake-up monitor and synchronous rectifier also acts as a near-idealdiode to rectify the current. An active charge indicator 310 detectswhen a personal electronic device is being charged and turns onlight-emitting diode 332.

In the initial rectifier 302, a neutral AC line feeds one side of adiode bridge 312, while a hot AC line feeds the other side through aprotective fuse 314. The rectified current is provided to the flybackcontroller 304, which is based on a UCC28730 integrated circuit 316. Theflyback controller switches the current through primary winding 318 oftransformer 306, and monitors the current through auxiliary winding 320of the transformer. The winding ratios of transformer 306 may differ indifferent embodiments of the invention intended for sale in differentregions of the world, as appropriate to the standard household outletvoltage of the region.

When there is no load, wake-up monitor and synchronous rectifier 308,based on a UCC24650 integrated circuit 322, sends a series of pulsesthrough the transformer signaling the flyback controller 304 to shutdown, saving power when there is no device connected to the charger. AUCC24610 integrated circuit 324 provides the synchronous rectifierfunction, acting as a near-ideal diode providing high efficiency and lowvoltage or power loss.

Finally, active charge indicator 310 uses a comparator 326 provide avoltage difference across light-emitting diode 332 when a voltage dropacross filter inductor 328 indicates an active device is connected.Light-emitting diode 332 thus indicates when a connected personalelectronic device is being charged.

After the AC input is transformed and rectified, the internal battery ischarged with current provided through 5-volt output 330.

As shown in FIG. 6, an embodiment of the present invention may consistof separable modules, allowing the user to save space by attaching onlythe modules needed at any given time. This embodiment of mobile devicecharger 100 includes a wireless charging mat 404, in which is circuitrywhich receives DC power input and uses an inverter to transfer power toa primary coil, providing power via induction to a secondary orreceiving coil in a mobile device. The mat 404 stacks on top of anothermodule which provides the DC power input. Such a power source can be abattery module 406 which includes an internal battery, or a cord module408. The cord module 408 acquires power from an external power source toprovide to either a battery module 406 for charging its internalbattery, or directly to the charging mat 404. The cord module 408includes either a retractable USB cord configured to acquire powerthrough a USB port, a retractable electrical plug configured to acquirepower through a household power outlet, or both. Appropriate circuitryconverts the power to the necessary DC output for the mat 404 or thebattery module 406.

The mat 404 is shown stacked on top of the battery module 406, which inturn is stacked on the cord module 408, allowing the internal battery ofthe battery module 406 to be charged while power is provided to the mat404 for charging a mobile device. If no power outlet is available, auser may stack the mat 404 on the battery module 406 alone and omit thecord module 408. If a power outlet is available and the user wishes tosave space, the mat 404 may be stacked directly onto the cord module408, omitting entirely the battery module 406.

FIG. 7 shows an embodiment of the present invention configured forpositioning a mobile device charger 100 at an angle for convenient useof a mobile device during charging. A charging mat 440 comprises a powersource 206, an inverter 208, a primary coil 210, a voltage sensor 212,and a controller circuit 214 as shown in FIG. 4. Attached to the bottomof the charging mat 440 is a lever 442 which, in a first configuration,sits flush with the charging mat 440. The lever 442 is attached to thecharging mat 440 via a hinge, which allows the lever 442 to pivotoutward into alternate configurations. The lever 442 is configured tolock into alternate configurations at desired angles. One way in whichthis may be accomplished is via a base 444 attached to one end of thecharging matt 440 via a hinge. The base 444 would normally sit in afirst configuration flush with the charging mat 440, and covering thelever 442 sitting in its first configuration. When folded outward, thelever 442 would be held in each of its configurations via stoppers 446on the base 444. Stoppers 446 are preferably grooves in the base 444 orridges on the base 444 which allow the lever 442 to be held in place.

While the above is a description of various embodiments of the presentinvention, further modifications may be employed without departing fromthe spirit and scope of the present invention. Thus the scope of theinvention should not be limited according to these factors, butaccording to the following claims.

What is claimed is:
 1. An inductive mobile device charger comprising: acharging mat module comprising an inductive charging circuit comprisinga coil configured to provide power to a mobile device through apulsating magnetic field; and a plurality of power input modules, eachpower input module removably attachable to the charging mat module, theplurality of power input modules comprising: a battery module comprisinga battery, and a cord module comprising a power converter circuit and acord configured to connect to an external power source, wherein: eachpower input module is configured to provide power to the inductivecharging circuit when the battery module is attached to the charging matmodule, the cord module is configured to removably attach to the batterymodule, the cord module is configured to charge the battery of thebattery module when the cord module is attached to the battery module,and the charging mat module is operable when any one of the power inputmodules is attached to the charging mat module.
 2. The inductive mobiledevice charger of claim 1, further comprising a base module attachableto a bottom of the mobile device charger and comprising a stand, thestand comprising a lever which sits flush against the base module in afirst configuration and pivots outward locking at an angle in a secondconfiguration.
 3. The inductive mobile device charger of claim 1,wherein the inductive charging circuit comprises: a power source; acoil; an inverter configured to provide power in the form of analternating current waveform to the coil; a voltage sensor; and acontroller configured to respond to a signal detected by the voltagesensor by causing the inverter to change the amount of power provided tothe coil.
 4. The inductive mobile device charger of claim 1, wherein thecord module comprises a USB cord configured to acquire power through aUSB port.
 5. The inductive mobile device charger of claim 4, wherein theUSB cord is retractable.
 6. The inductive mobile device charger of claim1, wherein the cord module comprises an electrical plug configured toacquire power through a household power outlet.
 7. The inductive mobiledevice charger of claim 6, wherein the electrical plug is retractable.8. The inductive mobile device charger of claim 1, wherein the inductivecharging circuit comprises a controller circuit configured to receivecommunications from the mobile device requesting an amount of powerneeded.
 9. The inductive mobile device charger of claim 8, wherein thecommunications from the mobile device are accomplished throughbackscatter modulation.
 10. The inductive mobile device charger of claim8, wherein the communications from the mobile device are accomplishedthrough frequency-shift keying.
 11. A stackable mobile device charger,comprising: a charging mat module operable to provide power to a load; abattery module comprising a battery and operable to provide power to thecharging mat module and to receive power to charge the battery; and acord module comprising a power converter circuit and a cord configuredto connect to an external power source, the cord module operable toprovide power to the charging mat module or the battery module, whereinthe charger comprises at least three configurations in which thecharging mat module is operable, the configurations comprising: a firstconfiguration wherein the charging mat module is stacked on top of thebattery module and receives power from the battery module; a secondconfiguration wherein the charging mat module is stacked on top of thecord module and receives power from the cord module; and a thirdconfiguration wherein the charging mat module is stacked on top of thebattery module, and the battery module is stacked on top of the cordmodule, the charging mat module receiving power from the battery moduleand the battery module receiving power from the cord module.
 12. Thestackable mobile device charger of claim 11, wherein the cord of thecord module is retractable.
 13. The stackable mobile device charger ofclaim 11, wherein the cord of the cord module comprises a USB connector,and the cord module is configured to receive power from a USB port. 14.The stackable mobile device charger of claim 11, wherein the cord of thecord module comprises an electrical plug and the cord module isconfigured to receive power through a household power outlet.
 15. Thestackable mobile device charger of claim 11, further comprising asecondary coil configured to allow the battery module to receive powerfrom an inductive mobile device charger.
 16. The stackable mobile devicecharger of claim 11, wherein the charging mat module comprises aninductive charging circuit configured to provide power to the load. 17.The stackable mobile device charger of claim 16, wherein the inductivecharging circuit comprises a controller circuit configured to receivecommunications from the mobile device requesting an amount of powerneeded.
 18. The stackable mobile device charger of claim 17, wherein thecommunications from the mobile device are accomplished throughbackscatter modulation.
 19. The stackable mobile device charger of claim17, wherein the communications from the mobile device are accomplishedthrough frequency-shift keying.
 20. An inductive mobile device charger,comprising: an enclosure having a top end and a bottom end; anelectrical plug on the bottom end of the enclosure; and an inductivecharging circuit, wherein the inductive charging circuit comprises: apower source; a coil; an inverter configured to provide power in theform of an alternating current waveform to said coil; a voltage sensor;and a controller configured to respond to a signal detected by thevoltage sensor by causing the inverter to change the amount of powerprovided to the coil.